Electrohydrodynamic impulse printing PANI sensor for NH 3 gas

Electrohydrodynamic impulse printing is utilized to fabricate polyaniline droplets from protonic acid doped polyaniline, which can be composed to form lines as micro NH₃ sensing elements. The effect of applied voltage, voltage frequency and voltage duty ratio on pattern size is investigated. The results show the size decreases with the frequency and voltage, but increases with the duty ratio. A minimum width line of 92 µm is obtained when applied voltage, voltage frequency, duty ratio, nozzle tip to substrate distance and flow rate are set to be 2450 V, 40%, 70 Hz, 1 mm and 100 µl/h, respectively. When exposed to NH₃ gas, electrohydrodynamic printed polyaniline lines have a rapid response time to NH₃. A minimum concentration of about 300 ppm of NH₃ can be detected.